Magnetovolume effect in ferromagnetic metals

It is shown that the magnetovolume effect in ferromagnetic metals can be estimated by using two functions, b(M,V)= delta F(M,V)/ delta M and p(M,V)=- delta F(M,V)/ delta V, where F(M,V) is the free energy of the system with magnetic moment M and volume V. The magnetovolume effect in ferromagnetic BCC iron at zero temperature is estimated numerically by using the spin density functional formalism. The band structure used in the numerical calculation is obtained by the linear muffin-tin orbital method. The calculated results of the magnetovolume effect indicate the necessity to improve the local spin density approximation in the ferromagnetic state.